title: On-line breath analysis with PTR-TOF.
abstract: We report on on-line breath gas analysis with a new type of analytical instrument, which represents the next generation of proton-transfer-reaction mass spectrometers. This time-of-flight mass spectrometer in combination with the soft proton-transfer-reaction ionization (PTR-TOF) offers numerous advantages for the sensitive detection of volatile organic compounds and overcomes several limitations. First, a time-of-flight instrument allows for a measurement of a complete mass spectrum within a fraction of a second. Second, a high mass resolving power enables the separation of isobaric molecules and the identification of their chemical composition. We present the first on-line breath measurements with a PTR-TOF and demonstrate the advantages for on-line breath analysis. In combination with buffered end-tidal (BET) sampling, we obtain a complete mass spectrum up to 320 Th within one exhalation with a signal-to-noise ratio sufficient to measure down to pptv levels. We exploit the high mass resolving power to identify the main components in the breath composition of several healthy volunteers.
authors.affiliation: Ionimed Analytik GmbH, Innsbruck, Austria.
authors.forename: Jens
authors.initials: J
authors.lastname: Herbig
authors.forename: Markus
authors.initials: M
authors.lastname: Müller
authors.forename: Simon
authors.initials: S
authors.lastname: Schallhart
authors.forename: Thorsten
authors.initials: T
authors.lastname: Titzmann
authors.forename: Martin
authors.initials: M
authors.lastname: Graus
authors.forename: Armin
authors.initials: A
authors.lastname: Hansel